Many search engine services, such as Google and Overture, provide for searching for information that is accessible via the Internet. These search engine services allow users to search for web pages and other Internet-accessible resources that may be of interest to users. After a user submits a search request that includes search terms, the search engine service identifies web pages that may be related to those search terms. To quickly identify related web pages, the search engine services may maintain a mapping of keywords to web pages. This mapping may be generated by “crawling” the web (i.e., the World Wide Web) to identify the keywords of each web page. To crawl the web, a search engine service may use a list of root web pages to identify all web pages that are accessible through those root web pages. The keywords of any particular web page can be identified using various well-known information retrieval techniques, such as identifying the words of a headline, the words supplied in the metadata of the web page, the words that are highlighted, and so on. Some search engine services can even search information sources that are not accessible via the Internet. For example, a book publisher may make the content of its books available to a search engine service. The search engine may generate a mapping between the keywords and books. When a search engine service receives a search request that includes one or more search terms, it uses its mapping to identify those information sources (e.g., web pages or books) whose keywords most closely match the search terms. The collection of information sources that most closely matches the search terms is referred to as the “search result.” The search engine service then ranks the information sources of the search result based on the closeness of each match, web page popularity (e.g., Google's page ranking), and so on. The search engine service then displays to the user links to those information sources in an order that is based on their rankings.
Some search engine services do not charge a fee to the providers of web pages for including links to their web pages in search results. Rather, the search engine services obtain revenue by placing advertisements along with search results. These paid-for advertisements are commonly referred to as “sponsored links,” “sponsored matches,” or “paid-for search results.” A vendor who wants to place an advertisement along with certain search results provides a search engine service with an advertisement and search terms. When a search request is received, the search engine service identifies the advertisements whose search terms most closely match those of the search request. The search engine service then displays those advertisements along with the search results. If more advertisements are identified than will fit on the first page of the search results, the search engine service selects to display on the first page those advertisements belonging to the vendors that have offered to pay the highest price (e.g., placed the highest bid) for their advertisements. The search engine services can either charge for placement of each advertisement along with search results (i.e., cost per impression) or charge only when a user actually selects a link associated with an advertisement (i.e., cost per click).
Advertisers would like to maximize the effectiveness of advertising dollars used to pay for advertisements placed along with search results. Thus, advertisers try to identify search term and advertisement combinations that result in the highest benefits (e.g., most profit) to the advertiser. Many techniques have been developed to identify search terms that may be appropriate for advertising various items. For example, some techniques analyze “clickthrough logs” to identify search requests submitted by users and the items of sponsored links that the users selected. If many search requests with a common search term result in users selecting sponsored links for the same item, then a vendor may want to place an advertisement for that item in any search request that contains that search term. Some techniques also select search terms based on “conversion rate” for a search term and an item. A conversion rate is a measure of the percentage of clickthroughs to the item resulting in an actual purchase of the item. Conversion rate, however, is more generally the percentage of clickthroughs that result in some desirable benefit to a vendor or an organization. For example, the conversion rate for an insurance company may be a measure of the percentage of clickthroughs that result in the user requesting a rate quote.
It is important for vendors to have an effective advertisement plan for new release items (i.e., items not yet released or recently released items). If a vendor can effectively advertise new release items (e.g., books, DVDs, or CDs), the vendor can capitalize on the intense consumer demand that often surrounds the release of an item. Traditional techniques such as analyzing clickthrough logs are not particularly effective for new release items. Among other drawbacks, such techniques rely on historical clickthrough patterns, which are not available for new release items.